A Timeline of The Featherweight Motor
The Motor is one of the most vital parts on the Singer Featherweight. It is likely to be the first part to display signs of age on almost any machine, so it is important that the motors are properly cared for. When a motor does wear out, it can be replaced by any original Featherweight motor. (It can also be rewound, maintaining originality, but we will address that later.) Of course, there would be exceptions but having the original motor on a Featherweight does not necessarily increase monetary value, but it can add to the appeal and sentimentality of the machine.
In this post we will be looking at the various markings of the motors and in particular, the series number in the lower right hand corner, on the top of the band (see photo below.) 
These numbers indicate the motor series. Many Featherweight motors were the same voltage, amperage and category, but these small codes indicate the motor model, and can give clues to its era.
Most black motors look very similar, but an interesting characteristic is that Singer did have three different Red "S" symbols that they used on the metal motor bands (see photo below). Note: a Red "S" on a motor does not indicate that a Featherweight machine is in the Red "S" category.
Below is a timeline that reflects all the motors we have observed over several years of Featherweight collecting and servicing.
US Motors:
We have recorded a total of nine different US Featherweight motor series'. The motors built in the Elizabethport, NJ factory have metal housings, and 3/8" motor cap screws, and the metal pulleys attach to the armature at the flat spot.
Bakelite motors have Bakelite housings,1/2" motor cap screws, and the Bakelite pulley attaches to the completely round shaft through the screw hole. 
Featherweight Motor Plate Housing styles
Motor Pulley styles - Bakelite and Metal
Motor Caps in Two Sizes - 1/2 inch and 3/8 inch
First Series (No Markings) 1933-1935:
This is the first Featherweight motor series, and it was manufactured from 1933 into mid 1935. It has no markings in the lower right corner and the Red S on the band is enclosed by an outer ring.
700 Series 1935-1948:
The second series US Featherweight motor was the first with a series #. It is the same as the previous motor with the addition of only the "700" series stamp. This motor was standard issue on all US Featherweights from mid 1935 to 1948.
700F Series 1948:
This motor is a scarce one. It appears to have been issued when Singer transitioned from the 700 series to the next 678-3 series. We have only seen a couple of these motors, and they were from early 1948.
Photo by Susan W.
678-3 Series 1948-1950:
This new US series motor is the first with a bolder Red S in the silver circle design on the motor band. The 678-3 motor series started in 1948 and went into mid 1950.
678-3A Series 1950-1952:
Singer made several different motors within the greater 678-3 category, but they are all very similar in appearance. The 678-3A was used from 1950 into later 1952.
678-3B Series 1952-1953:
With the 678-3B series the Red S on the motor band changed to the standard Singer Sewing Machines "S" with no circle or ring. This series motor was used from late 1952 to late 1953.
G678-4 Series 1954-1956:
The "G" series US motors came out about the same time as the paperclip decals on the Featherweight, and were the last ones issued in the US. The G678-4 series was manufactured from 1954 into 1956.
G678-04 Series 1957:
The last standard issue US motor was issued in late 1956 through 1957.
Rare and Undated US Motors
There are some US Featherweight motors that have been found, but unfortunately there isn't a record of serial numbers to date them accurately. Below are a couple of very uncommon motor series styles.
1601-1A:
Gold "S" Bakelite US made 110v.
The Gold "S" motors are unique in style and the history behind them is relatively unknown. They were the first motors issued with 221 models made in the UK as 220 voltage, but this style has also been found in Canada and the US with 110 voltage. The one shown below is a 110V motor stamped "made in the USA", but it is unlikely that it was made in America from start to finish. The clue here is that these motors have a Bakelite housing, but US motors originally had metal housings. Our assumption then is that these gold "S" motors were actually sourced from the UK, but those needing 110v wiring finished their manufacturing process and were wound in the US and/or Canada. Singer did this with other parts, so it is not out of the ordinary to assume they would have done this with motors also. For example, some machines were stamped with "Made in Canada" even though those items originated from the UK. If the St. John's factory in Canada handled the finishing process like badging or making controllers and motors, then they would indicate that these machines were "Made in Canada." It is conjecture, but perhaps this dual manufacturing helped Singer legally avoid tariffs or import fees when shipping unfinished product between their manufacturing plants.
If we were to find concrete evidence about these motors, (original diagrams and notes from Singer) that would certainly help to confirm the history of these motors. We will always update our pages should any more information surface.
US Gold "S" 110v
Canada Gold "S" 110v
UK Gold "S" 220v
If you have other US motors with "Series #s" not shown here, please contact us.
Canadian Motors:
There are several different "Canadian" Featherweight motors, but as indicated above, they were actually made in the UK and US but finished their manufacturing process in Canada. Some Canadian motors are metal and some are Bakelite, and as always there are a few series that are more scarce than others. We have observed a total of six confirmed black motors and one tan motor style that have the Canadian indication.
1520 Series 1947-1950:
The 1520 series Featherweight motors are the earliest confirmed Canadian motors, and they were issued on 221K machines in the late 1940s. Not many of these motors exist. It was also around this time period when Featherweights were first marketed in Canada. The 1520 series motor is almost always 110V, but we have seen a very rare 220V 1520 series motor as well. It is very peculiar to us as to why a 220V motor would have ever been manufactured in Canada.
Photographed by Andrea O.
1520-1 Series 1946-1948
The "1520-1" series motors came after "1520", and were issued with 221 models made in the US and a few made in the UK. When Singer first sold UK made Featherweights in Canada they also sold US made Featherweights; this is why 1946-1948 US machines can also be found with these "1520-1" motors.
1600A Series 1949-1953:
After the "1520" motor series Singer issued the "1600" series motors. The first confirmed is the "1600A," and it was used on UK made 221 machines and early 222 machines from late 1949 through early 1953.
1600-4 Series 1952-1961:
The "1600-4" series Canadian motor is likely the most common Canadian motor. It can be seen on 221K and 222K machines anywhere from 1952 through 1961.
1600-04 Series 1960-1961:
This is the last confirmed Canadian black motor, and it was used in the late 1960s on 221K and 222K machines.
Photo by John P.
UK Motors:
Some of the most peculiar motors are those that were manufactured in the UK. All the UK made motors had Bakelite housings, 1/2" motor caps, and motor pulleys, plus, the motors themselves can often be more complex. In the UK, Singer used the same motor series for motors of different voltages and electrical ratings, so categorizing these motors can be very difficult. The various UK motor series were usually categorized based on the countries where the motors were going to be used and not necessarily based on when the motors were produced. Because of this, we have not yet been able to find accurate motor dates. Below are some of the various UK motors along with some of the oddities that we have logged over the years.
Gold "S" 220V Great Britain Series
As mentioned earlier, the Gold "S" motors were marked as though they were made in the UK, Canada and the US, but it appears as if all of them were mostly assembled in Great Britain. This was the first motor used on 221K machines, and it can be found from 1947 into early 1948.
1783 Series:
There are a total of six prefixes in this "1783" series and almost all are UK made Featherweight motors. "1783" seems to be the first numbers used, and they can be found on motors with both 220 voltage and 110 voltage (occasionally used in France). To read more about the voltage requirements in France click here. These motors appear to be an earlier Great Britain motor style, having chrome boxes on the motor band with etched voltage and amperage information. This would have been easier for Singer to use the same band when making a motor either 110 or 220 volt.
1783-1 Series:
While we don't know when this series was produced, it appears to be next in line after the standard "1783" series. We have only seen this "1783-1" series in 110V, but it is possible it was made in 220V as well.
Notice the "AP" decals on the side of this motor. This was something Singer indicated for their UK 110V motors going to France. The initials reference is found on almost all UK motors sent to countries with an alternate power voltage.
1783-IA Series:
The 1783-1A is another motor that we have only seen in 110V.
Photo by Julia L.
1783A Series:
The "1783A" is another motor that we have only seen in 110v. This particular motor has an "SI" stamp on the top. The SI indication stands for System International, and has electrical references similar to the "AP" stamp as noted above.
1783-4 Series:
The motor below is a standard 220v UK motor. We have not been able to confirm very many details about this motor, but it has been observed on machines from 1957.
1783-4A Series
The 1783-4A series is another motor that has been observed with the "SI" decal. In this instance, the motor is 220V contrasted with the 110V "1783-1A" series.
1783-5
The "1783-5" series motors are the most common 220V motor. They have been observed on both 221K and 222K machines from 1952-1960.
One variation of the "1783-5" series has an "A" on the badge. This was a marking similar to the SI, and used for electrical regulations in other countries.
Photo provided by Patsy T.
UK Built Motors With No Series Numbers:
There were also motors built in the UK that have no series numbers. We do not know if these were issued before or after the number series motors, but they have been found in either 110 or 220 voltage.
Replacement motors made in the UK:
Featherweights and their parts were still being made in the UK through about 1969, even after the factory in the US had ceased their production 12 years earlier. Because of this, replacement parts for US machines sometimes had to be sourced from the UK plant. Below is a photo of a replacement motor for a black Featherweight. This motor is the same motor as the later White Featherweight motors, but it is black instead of white.
Tan Featherweight Motors:
Tan Featherweight motors were always made in Canada, and they are very similar to the black "1600-04" series motors. History on the tan and white Featherweight machines can be inconclusive (records were poorly maintained), but thankfully the motors have their tell-tale clues and indicators. We have only observed one series of tan motors on all tan Featherweights - 1-991600-05.
White Featherweight Motors:
White Featherweight motors came in 110V and 220V, but they were all made in Great Britain. There weren't any "series" numbers on the white Featherweight motors, but they were two variations. The earlier white Featherweight motors had lubrication ports, but motors issued later were sealed. These later white Featherweight motors had bushings infused with oil, so they do not need any additional lubrication from either the outside or inside.
Note the lubrication ports on the white Featherweight motor above. Proper lubrication is needed for this style.
A sealed Featherweight motor with no lubrication ports. Lubrication is not required.
Motor FAQs:
1. Are the motors interchangeable?
Yes, all the Featherweight motors mount to the machine in similar fashion, and each motor has two lead wires. The wires do wire in differently to the connectors inside a White Featherweight, but any motor can fit. Though a 110V motor and 220V motor are interchangeable in how they fit on the machine, they can only run on their specified power. If you have a 222 originally fitted with a 220v motor, you can replace it with a 110V motor and run the machine with 110V power.
2. Can I take the insides of a new replacement generic Featherweight motor, and put them in my original Singer motor?
No, generic motors are not made to the same specifications as the Singer motors, so this swap cannot be made. If a Featherweight armature is running very poorly, we recommend that you first send it in to our shop for service. If the armature is beyond what an ordinary service can remedy, we do offer a motor rewinding service. (This would be like getting a brand new, powerful motor on the inside, yet maintaining the original cosmetic appearance of the exterior.) Feel free to contact us about our motor services.
3. How do I maintain my motor?
The Featherweight motors do have very specific maintenance requirements, but with the proper tools, the motor can be perfectly maintained right at your sewing table. Click here for information on maintaining your motor.
4. Are some Featherweight motors better than others?
That is an excellent question and one that we are still researching. Singer had many, many different armatures and motor windings, so they are not all created equal. Stay tuned as we will be updating this post with our findings.
Before reading this article, how many Featherweight motor styles would you have thought Singer manufactured? Perhaps, three? - a black, tan and a white one? Well, even we were surprised to see 30+ different motor series and variations in our research. If you have a motor series or strange markings that are not listed here ore referenced on our foreign Featherweights article, please contact us, so that we can keep this post as relevant as possible.